If you're looking at a commercial roof replacement, you've probably got a flat roof in mind.
Interestingly, most of the roofs we consider flat are in fact low-slope roofs. These have a slope of 2:12 or 4:12, so they fall under OSHA's definition of a low-slope roof.
The reason for this slight gradient is because water dams form more easily on flat roofs.
You have several options when it comes to choosing low-slope commercial roofing types. These are the most common commercial roof systems available today.
Built-Up Roofing Systems
BUR consists of alternating layers of hot bitumen and fiberglass asphalt sheeting to create a watertight seal. The top of this roofing consists of gravel or crushed rock impressed into the final asphalt layer to help hold it all down.
Built-up roofing systems boast excellent durability and good fire ratings. They can last up to 20 years but take longer to install, resulting in higher labor costs.
Modified Bitumen Commercial Roofing
These roofs comprise asphalt mixed with chemical polymers that add increased flexibility to the roofing system. Most modified bitumen roofs have five layers.
Insulation for better temperature stability
Modified base sheets
Sheet membrane comprising reinforced co-polymer
A waterproof adhesive with a bonding agent
A top surface that provides UV protection and weather resistance
After installing the layers on your roof, your contractor uses a blowtorch to melt them all together, forming a secure bond.
This type of roof offers outstanding protection against extreme temperatures, fire, wind, and hail and they're quicker to install than BUR.
Single-Ply Commercial Roofing Types
These types of commercial roofs offer excellent flexibility and durability. They consist of a single layer of roofing material placed on top of a concrete deck.
There are three main varieties of single-ply roofing systems. These are:
Polyvinyl Chloride (PVC)
Thermoplastic Polyolefin (TPO)
Ethylene Propylene Diene Monomer (EPDM)
These roofs are energy-efficient and TPO roofing's recyclable too, so they're an eco-friendly choice.
The right roofing contractor can help you make a choice when you're figuring out how to choose a commercial roof of this type for your building.
Metal Commercial Roofing
While metal's a great option for residential roofing, it's one of the less popular commercial roof materials available today.
That's because metal roofing gets expensive when you need to install it in large quantities. Metal roofs offer excellent durability and look good on most buildings. They have an excellent fire rating and are impervious to dents and punctures.
Metals used in these applications include:
Corrugated galvanized steel
Some metals corrode over time. To prevent this, you can install sheets treated with a protective layer that also adds extra weather resistance.
More Options for Your Commercial Building
There are a few other less common commercial roofing types used by some enterprises today. These include green roofs, liquid-applied roofing, and roof coating systems.
An experienced roofing contractor can fill you in on the details about these. For other helpful snippets about refurbishing your commercial building, explore our website.